The Higgs boson is a hypothetical massive scalar elementary particle predicted to exist by the Standard Model in particle physics. At present there are no known fundamental scalar particles in nature.

The Higgs boson is the only Standard Model particle that has not been observed. Experimental detection of the Higgs boson would help explain the origin of mass in the universe. The Higgs boson would explain the difference between the massless photon, which mediates electromagnetism, and the massive W and Z bosons, which mediate the weak force. If the Higgs boson exists, it is an integral and pervasive component of the material world.

The Large Hadron Collider (LHC) at CERN, which became fully operational on November 20, 2009[1], is expected to provide experimental evidence of the existence or non-existence of the Higgs boson. Experiments at Fermilab also continue previous attempts at detection, albeit hindered by the lower energy of the Fermilab Tevatron accelerator. It has been reported that Fermilab physicists suggest that the odds of Tevatron detecting the Higgs boson are between 50% and 96%, depending on its mass